This invention relates generally to irrigation sprinklers, and more particularly to a new and improved low volume mini-sprinkler irrigation stake assembly, and to a new and improved dual pattern mini-sprinkler unit including a deflector specifically adapted for efficient irrigation of trees in an orchard.
Low volume mini-sprinkler systems have particular advantages over other types of sprinkler irrigation systems when used for watering plants and trees typically grown in orchards, vineyards, nurseries, greenhouses, and the like since they operate at relatively low supply pressures and flow rates, typically between 10 and 30 psi and between 5 and 30 GPH to save water, and produce spray patterns that are relatively close to the ground to minimize water loss due to wind drift. Further, such systems are relatively low in cost, energy efficient, easy to install and maintain, and can be readily changed, moved or modified to meet varying irrigation demands.
In a typical mini-sprinkler system installation such as used for irrigating plants and trees grown in side-by-side rows, main water supply conduits are laid along each row and coupled to a source of pressurized water. Mini-sprinkler units are then installed adjacent each plant, and the mini-sprinklers are each coupled with the main conduit, typically through small diameter, flexible branch tubes. Depending upon the type, age, and spacing between plants or trees, one mini-sprinkler unit may be used to water one or several adjacent plants or trees. Further, the type of plant or tree, its age and size, and the purpose of water application determine the type of mini-sprinkler unit to be used.
There are many different types of mini-sprinkler units available on the market, some intended to produce a spray pattern in the form of individual streams, and others which produce a fan-shaped spray. Some produce spray patterns that cover a substantially circular area about the sprinkler, and others produce spray patterns that cover only a segment of a circular area. A typical mini-spray unit comprises a nozzle which ejects a substantially vertical water stream into the atmosphere and a deflector overlying the nozzle which deflects the stream laterally of the sprinkler with the desired spray pattern. Exemplary of such mini-sprinkler units are those illustrated in the 1990 Rain Bird Agricultural Equipment catalogue at pages 5 through 8.
In most cases, each mini-sprinkler unit is intended to be coupled to the end of the branch tube and supported adjacent the plant or tree by a ground penetrating stake which typically includes means for directing and holding the branch tube so that the mini-sprinkler unit projects vertically above the stake. One such stake is that described in U.S. Pat. No. 4,944,476 issued Jul. 31, 1990, and another is illustrated in U.S. Design Pat. Des. No. 313,339 issued Jan. 1, 1991.
Since it is frequently desirable to be able to change mini-sprinkler units from time to time, such as to replace a worn deflector, clean out a plugged nozzle, or to alter the nozzle size or the spray pattern such as may be required as the plant matures or to apply fertilizer or other liquid plant treatment during selected irrigation periods, it is important that the mini-sprinkler unit be capable of being easily and quickly coupled to and uncoupled from the branch tube. Thus, most mini-sprinkler units include a coupling between the sprinkler and the branch tubing which can be released. In some cases, that coupling may be a simple barb or threaded portion on the mini-sprinkler unit which can be pushed or threaded into the end of the branch tubing directly, and in others, a twist-lock coupling is used, the twist-lock coupling typically comprising a coupler element having a barbed end inserted into the branch tubing and carrying coupling flanges which receive cooperating coupling ears formed on the mini-sprinkler unit.
One problem which has been found with prior art mini-sprinkler stake assemblies is that the barbed or threaded coupling of the mini-sprinkler unit to the branch tube may become loose during use, thereby permitting the mini-sprinkler unit to rotate relative to the stake and tube so that the spray pattern is no longer projected in the desired direction. Another problem is that the mini-sprinkler unit may actually "blow-out" and separate from the branch tube as a result of the barbed or threaded coupling becoming loose.
Moreover, since it is desirable to be able to change the spray pattern from time to time, care must be taken to insure that the different mini-sprinkler units all employ the same type of coupling. That is, if the mini-sprinkler unit in use has a twist-lock coupling with the branch tube, a new mini-sprinkler to be used must also have a twist-lock coupling. Thus, it would be desirable to have a universal mini-sprinkler stake assembly that could be used with mini-sprinkler units having substantially any type of coupling for connection with the branch tube. As will become more apparent hereinafter, the present invention provides a new and improved mini-sprinkler stake assembly which includes a universal coupling means for permitting substantially any mini-sprinkler unit to be quickly and easily coupled with the branch tubing, and which prevents sprinkler rotation and blow out.
Another problem which has been encountered is that typical prior art mini-sprinkler units do not lend themselves to alteration so that if a particular flow rate or spray pattern is desired, a user must obtain a mini-sprinkler unit having the desired flow rate and pattern. The present invention provides a new and improved mini-sprinkler unit which includes a separable nozzle element and dual pattern deflector so that the user can quickly and simply alter the flow rate by selecting the appropriate nozzle element and/or quickly and easily change the spray pattern by reversing the deflector element without having to replace the entire mini-sprinkler unit.
A further problem that has long plagued the irrigation field is that of effectively irrigating trees in an orchard such that the water is applied uniformly over only the root zone area around each tree, and does not spray on the tree trunks nor in the areas between trees where unwanted weeds or other plants may grow. As will also become more apparent hereinafter, the present invention provides a unique spray deflector configuration for a mini-sprinkler unit which insures uniform water application to the root zone areas around the trees of an orchard without applying water to the trunks of the trees or in the areas between trees.